Changed how default value is now _ for tapes

transition_machine/src/Config.cpp

@@ -202,7 +202,7 @@ void Config::printAsOutput(FILE * output, int dataIndex, int realIndex)
   for (unsigned int j = 0; j < tapes.size(); j++)
   {
     if(bd.mustPrintLine(j))
-      toPrint.emplace_back(tapes[j][dataIndex-head].empty() ? "0" : tapes[j][dataIndex-head].c_str(), tapes[j].getEntropy(dataIndex-head));
+      toPrint.emplace_back(tapes[j][dataIndex-head].empty() ? "_" : tapes[j][dataIndex-head].c_str(), tapes[j].getEntropy(dataIndex-head));
   }
 
   ProgramOutput::instance.addLine(toPrint, realIndex);